Free Space Optical Communications With Blockage-Triggered Power Control
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Solution Overview
Problem
Existing FSO systems face challenges in balancing high data rate and long-distance coverage with human safety, particularly in terrestrial wireless communication scenarios where optical paths pass through areas with people, necessitating low transmission power that limits coverage and data rate.
Innovation Solution
Implementing wireless detection signals different from the optical signal to detect blockages and adjust transmission intensity or suspend the optical signal accordingly, ensuring safety by using signals safe for human eyes to form a 'fence' around the optical path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high transmission power is used to achieve long-distance coverage and high data rate, then coverage distance and data rate are improved, but human safety is compromised due to strong optical signal irradiation
Solution Approach 1:
The system performs preliminary detection of the optical path using detection signals before actual data transmission. This preliminary action identifies potential human presence or obstacles in advance, allowing the system to prevent harmful irradiation before it occurs while maintaining the ability to transmit at high power when safe
Solution Approach 2:
The system continuously monitors the optical path using detection signals and feeds back information about human presence or blockages to the transmission control. Based on this feedback, the system dynamically adjusts transmission power or suspends transmission to protect human safety while maintaining high data rate capability when the path is clear
2Object-affected harmful factors
If low transmission power is used to protect human eyes, then human safety is improved, but coverage distance and data rate are reduced
Solution Approach 1:
The system dynamically adjusts transmission power based on real-time detection of the optical path environment. When no humans are detected, the system operates at high power for maximum data rate; when humans are detected, it automatically reduces power or suspends transmission. This dynamic adaptation resolves the contradiction by making transmission power flexible rather than fixed
3Productivity
If narrow directional beam is used to achieve high data rate, then data rate is improved, but system complexity increases due to need for blockage detection and dynamic adjustment
Solution Approach 1:
The system introduces detection signals as an intermediary mechanism to monitor the optical path. These detection signals act as mediators between the transmission system and the environment, providing information about human presence or obstacles that enables safe operation without requiring complex real-time processing or control systems
Data Source
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AI summary
Disclosed are a free space optical communications method, and a transmitter and a receiver. The method comprises: transmitting, by means of an optical signal, wireless data between a transmitter and a receiver; transmitting, between the transmitter and the receiver, a wireless detection signal different from the optical signal; detecting whether the wireless detection signal is blocked; and adjusting, according to a detection result, the transmission of the optical signal to reduce the intensity of the optical signal or suspend the transmission of the optical signal when the wireless detection signal is blocked.